This book provides the first general neurological theory of visual discomfort. The theory attributes the experience of visual discomfort to the strong physiological excitation that certain visual ...
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This book provides the first general neurological theory of visual discomfort. The theory attributes the experience of visual discomfort to the strong physiological excitation that certain visual stimuli give rise to, and the effects of such excitation when the visual cortex of the brain is hyperexcitable. Cortical hyperexcitability is now thought to occur in migraine as well as in epilepsy and other neurological disorders in which seizures are relatively common, such as autism. The theory explains why visual discomfort is experienced from flicker and from striped patterns; why fluorescent lighting and visual display terminals cause headaches; and why reading can give you tired eyes. The theory is based on the observation that people find certain specific visual patterns uncomfortable to look at, and that these same patterns can induce seizures in patients with photosensitive epilepsy. The spatial and temporal characteristics of the unpleasant visual stimuli are described in detail. The theory is applied to the design of lighting, the design of text, and indeed to design more generally. The use of ophthalmic tints to treat visual stress is introduced, and techniques for its prevention are discussed.Less

Visual Stress

Arnold J. Wilkins

Published in print: 1995-02-23

This book provides the first general neurological theory of visual discomfort. The theory attributes the experience of visual discomfort to the strong physiological excitation that certain visual stimuli give rise to, and the effects of such excitation when the visual cortex of the brain is hyperexcitable. Cortical hyperexcitability is now thought to occur in migraine as well as in epilepsy and other neurological disorders in which seizures are relatively common, such as autism. The theory explains why visual discomfort is experienced from flicker and from striped patterns; why fluorescent lighting and visual display terminals cause headaches; and why reading can give you tired eyes. The theory is based on the observation that people find certain specific visual patterns uncomfortable to look at, and that these same patterns can induce seizures in patients with photosensitive epilepsy. The spatial and temporal characteristics of the unpleasant visual stimuli are described in detail. The theory is applied to the design of lighting, the design of text, and indeed to design more generally. The use of ophthalmic tints to treat visual stress is introduced, and techniques for its prevention are discussed.

This introductory chapter discusses eye-strain as a physical consequence of visual stimulation, and then provides an overview of the remainder of the book. A general and unified theory of visual ...
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This introductory chapter discusses eye-strain as a physical consequence of visual stimulation, and then provides an overview of the remainder of the book. A general and unified theory of visual discomfort is provided in Chapters 2–4, and then applied to a variety of everyday problems, such as eye-strain from reading (Chapter 5), from lighting (Chapter 6), from television and visual display terminals (Chapter 7), and more generally from design (Chapter 8). The role of colour in therapy is reviewed in Chapter 9. Chapter 10 provides some theoretical speculations, and the Appendix gives a summary of techniques for preventing discomfort.Less

Introduction

Arnold J. Wilkins

Published in print: 1995-02-23

This introductory chapter discusses eye-strain as a physical consequence of visual stimulation, and then provides an overview of the remainder of the book. A general and unified theory of visual discomfort is provided in Chapters 2–4, and then applied to a variety of everyday problems, such as eye-strain from reading (Chapter 5), from lighting (Chapter 6), from television and visual display terminals (Chapter 7), and more generally from design (Chapter 8). The role of colour in therapy is reviewed in Chapter 9. Chapter 10 provides some theoretical speculations, and the Appendix gives a summary of techniques for preventing discomfort.

This chapter describes software emulators for the Pilot ACE. The first known software emulator of the Pilot ACE was built in Visual BASIC by Donald Davies in the early 1990s. In spring 2001, two ...
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This chapter describes software emulators for the Pilot ACE. The first known software emulator of the Pilot ACE was built in Visual BASIC by Donald Davies in the early 1990s. In spring 2001, two graduate students at the University of San Francisco, Athena Huang Shih-Yun and Nicola Rugai, ported Davies's code to Java as part of their Master's Project. Huang wrote additional Java code and improved and extended the interface. The improved emulator was written for The Turing Archive for the History of Computing and was inspired by the desire to offer a Pilot ACE emulation in a platform-independent format. Huang subsequently adapted the Pilot ACE emulator to the architecture of the Big ACE.Less

The Pilot Model and the Big ACE on the web

Benjamin Wells

Published in print: 2005-04-14

This chapter describes software emulators for the Pilot ACE. The first known software emulator of the Pilot ACE was built in Visual BASIC by Donald Davies in the early 1990s. In spring 2001, two graduate students at the University of San Francisco, Athena Huang Shih-Yun and Nicola Rugai, ported Davies's code to Java as part of their Master's Project. Huang wrote additional Java code and improved and extended the interface. The improved emulator was written for The Turing Archive for the History of Computing and was inspired by the desire to offer a Pilot ACE emulation in a platform-independent format. Huang subsequently adapted the Pilot ACE emulator to the architecture of the Big ACE.

Damage to a particular area of the brain — the neocortex — is generally understood to result in blindness. Studies of some patients who have suffered from this form of blindness have nevertheless ...
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Damage to a particular area of the brain — the neocortex — is generally understood to result in blindness. Studies of some patients who have suffered from this form of blindness have nevertheless revealed that they can, in fact, discriminate certain types of visual events within their ‘blind’ fields without being aware that they can do so: they think they are only ‘guessing’. This phenomenon has been termed ‘blindsight’ by the author of this book and his collaborators who were among the first to describe it. It continues to attract considerable interest among neuroscientists, psychologists, and philosophers who see possible implications for theories of perception and consciousness. This book gives an account of the research into a particular case of blindsight, together with a discussion of the historical and neurological background. The empirical findings are followed by a review of other cases reported by other investigators, in which there is a dysjunction between clinical assessment of blindness and unexpected findings of residual function. Finally, a number of theoretical and practical issues and implications are discussed. This reissued version of the text includes a new Introduction summarizing some of the advances that have taken place in the field since the book was first published in 1986.Less

Blindsight : A Case Study and Implications

L. Weiskrantz

Published in print: 1990-08-09

Damage to a particular area of the brain — the neocortex — is generally understood to result in blindness. Studies of some patients who have suffered from this form of blindness have nevertheless revealed that they can, in fact, discriminate certain types of visual events within their ‘blind’ fields without being aware that they can do so: they think they are only ‘guessing’. This phenomenon has been termed ‘blindsight’ by the author of this book and his collaborators who were among the first to describe it. It continues to attract considerable interest among neuroscientists, psychologists, and philosophers who see possible implications for theories of perception and consciousness. This book gives an account of the research into a particular case of blindsight, together with a discussion of the historical and neurological background. The empirical findings are followed by a review of other cases reported by other investigators, in which there is a dysjunction between clinical assessment of blindness and unexpected findings of residual function. Finally, a number of theoretical and practical issues and implications are discussed. This reissued version of the text includes a new Introduction summarizing some of the advances that have taken place in the field since the book was first published in 1986.

These fifteen chapters explore the ways in which recent developments in imaging, image analysis, and image display and diffusion can be applied to objects of material culture in order to enhance ...
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These fifteen chapters explore the ways in which recent developments in imaging, image analysis, and image display and diffusion can be applied to objects of material culture in order to enhance historians' understanding of the period from which the objects came (in this case, the remote past). In interpreting artefacts, the historian acts out a perceptual-cognitive task of transforming often noisy and impoverished signals into semantically rich symbols that have to be set within a cultural and historical context. Engineering scientists, equipped with a range of sophisticated techniques, equipment and highly specialised knowledge, are not always as aware as they might be of the range and the exact nature of problems faced by historians in interpreting objects of material culture. By providing the opportunity for scholars from these communities to explain to each other what they are doing and how, the chapters explore the ways in which the scientific contributors and the historians are thinking about subjectivity of interpretation, visual cognition, and the need to improve methods of presenting evidence so as to feed directly back into their own scientific thinking and to encourage genuine innovation in their approach to developing methods of image-enhancement and interpretation of objects. A significant further dimension is the improvement of techniques of providing high quality images of important and valuable collections of original artefacts to scholars who cannot always study the originals directly. Another important development discussed here is the fact that such imaging techniques now offer the researcher valuable insurance against the processes of deterioration to which such artefacts are inevitably subject. Seven of the chapters are scientific and technical, while the other eight have an archaeological or historical focus.Less

Images and Artefacts of the Ancient World

Published in print: 2005-05-26

These fifteen chapters explore the ways in which recent developments in imaging, image analysis, and image display and diffusion can be applied to objects of material culture in order to enhance historians' understanding of the period from which the objects came (in this case, the remote past). In interpreting artefacts, the historian acts out a perceptual-cognitive task of transforming often noisy and impoverished signals into semantically rich symbols that have to be set within a cultural and historical context. Engineering scientists, equipped with a range of sophisticated techniques, equipment and highly specialised knowledge, are not always as aware as they might be of the range and the exact nature of problems faced by historians in interpreting objects of material culture. By providing the opportunity for scholars from these communities to explain to each other what they are doing and how, the chapters explore the ways in which the scientific contributors and the historians are thinking about subjectivity of interpretation, visual cognition, and the need to improve methods of presenting evidence so as to feed directly back into their own scientific thinking and to encourage genuine innovation in their approach to developing methods of image-enhancement and interpretation of objects. A significant further dimension is the improvement of techniques of providing high quality images of important and valuable collections of original artefacts to scholars who cannot always study the originals directly. Another important development discussed here is the fact that such imaging techniques now offer the researcher valuable insurance against the processes of deterioration to which such artefacts are inevitably subject. Seven of the chapters are scientific and technical, while the other eight have an archaeological or historical focus.

More than one third of the human brain is devoted to the processes of seeing — vision is after all the main way in which we gather information about the world. But human vision is a dynamic process ...
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More than one third of the human brain is devoted to the processes of seeing — vision is after all the main way in which we gather information about the world. But human vision is a dynamic process during which the eyes continually sample the environment. Where most books on vision consider it as a passive activity, this book focuses on vision as an ‘active’ process. It goes beyond most accounts of vision where the focus is on seeing, to provide an account of seeing AND looking. The book starts by pointing out the weaknesses in our traditional approaches to vision and the reason we need this new approach. It then gives a thorough description of basic details of the visual and oculomotor systems necessary to understand active vision. The book goes on to show how this approach can give a new perspective on visual attention, and how the approach has progressed in the areas of visual orienting, reading, visual search, scene perception, and neuropsychology. Finally, the book summarizes progress by showing how this approach sheds new light on the old problem of how we maintain perception of a stable visual world.Less

Active Vision : The Psychology of Looking and Seeing

John M FindlayIain D Gilchrist

Published in print: 2003-08-07

More than one third of the human brain is devoted to the processes of seeing — vision is after all the main way in which we gather information about the world. But human vision is a dynamic process during which the eyes continually sample the environment. Where most books on vision consider it as a passive activity, this book focuses on vision as an ‘active’ process. It goes beyond most accounts of vision where the focus is on seeing, to provide an account of seeing AND looking. The book starts by pointing out the weaknesses in our traditional approaches to vision and the reason we need this new approach. It then gives a thorough description of basic details of the visual and oculomotor systems necessary to understand active vision. The book goes on to show how this approach can give a new perspective on visual attention, and how the approach has progressed in the areas of visual orienting, reading, visual search, scene perception, and neuropsychology. Finally, the book summarizes progress by showing how this approach sheds new light on the old problem of how we maintain perception of a stable visual world.

It has often been claimed that “monsters”—supernatural creatures with bodies composed from multiple species—play a significant part in the thought and imagery of all people from all times. This book ...
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It has often been claimed that “monsters”—supernatural creatures with bodies composed from multiple species—play a significant part in the thought and imagery of all people from all times. This book advances an alternative view. Composite figurations are intriguingly rare and isolated in the art of the prehistoric era. Instead it was with the rise of cities, elites, and cosmopolitan trade networks that “monsters” became widespread features of visual production in the ancient world. Showing how these fantastic images originated and how they were transmitted, this book identifies patterns in the records of human image-making and embarks on a search for connections between mind and culture. It asks: Can cognitive science explain the potency of such images? Does evolutionary psychology hold a key to understanding the transmission of symbols? How is our making and perception of images influenced by institutions and technologies? The book considers the work of art in the first age of mechanical reproduction, which it locates in the Middle East, where urban life began. Comparing the development and spread of fantastic imagery across a range of prehistoric and ancient societies, including Mesopotamia, Egypt, Greece, and China, the book explores how the visual imagination has been shaped by a complex mixture of historical and universal factors. Examining the reasons behind the dissemination of monstrous imagery in ancient states and empires, it sheds light on the relationship between culture and cognition.Less

The Origins of Monsters : Image and Cognition in the First Age of Mechanical Reproduction

David Wengrow

Published in print: 2013-11-24

It has often been claimed that “monsters”—supernatural creatures with bodies composed from multiple species—play a significant part in the thought and imagery of all people from all times. This book advances an alternative view. Composite figurations are intriguingly rare and isolated in the art of the prehistoric era. Instead it was with the rise of cities, elites, and cosmopolitan trade networks that “monsters” became widespread features of visual production in the ancient world. Showing how these fantastic images originated and how they were transmitted, this book identifies patterns in the records of human image-making and embarks on a search for connections between mind and culture. It asks: Can cognitive science explain the potency of such images? Does evolutionary psychology hold a key to understanding the transmission of symbols? How is our making and perception of images influenced by institutions and technologies? The book considers the work of art in the first age of mechanical reproduction, which it locates in the Middle East, where urban life began. Comparing the development and spread of fantastic imagery across a range of prehistoric and ancient societies, including Mesopotamia, Egypt, Greece, and China, the book explores how the visual imagination has been shaped by a complex mixture of historical and universal factors. Examining the reasons behind the dissemination of monstrous imagery in ancient states and empires, it sheds light on the relationship between culture and cognition.

This book presents a unified approach to understanding memory, attention, and decision-making. It shows how these fundamental functions for cognitive neuroscience can be understood in a common and ...
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This book presents a unified approach to understanding memory, attention, and decision-making. It shows how these fundamental functions for cognitive neuroscience can be understood in a common and unifying computational neuroscience framework. This framework links empirical research on brain function from neurophysiology, functional neuroimaging, and the effects of brain damage, to a description of how neural networks in the brain implement these functions using a set of common principles. The book describes the principles of operation of these networks, and how they could implement such important functions as memory, attention, and decision-making. The book discusses the hippocampus and memory, reward- and punishment-related learning, emotion and motivation, invariant visual object recognition learning, short-term memory, attention, biased competition, probabilistic decision-making, action selection, and decision-making.Less

Edmund T. Rolls

Published in print: 2007-08-02

This book presents a unified approach to understanding memory, attention, and decision-making. It shows how these fundamental functions for cognitive neuroscience can be understood in a common and unifying computational neuroscience framework. This framework links empirical research on brain function from neurophysiology, functional neuroimaging, and the effects of brain damage, to a description of how neural networks in the brain implement these functions using a set of common principles. The book describes the principles of operation of these networks, and how they could implement such important functions as memory, attention, and decision-making. The book discusses the hippocampus and memory, reward- and punishment-related learning, emotion and motivation, invariant visual object recognition learning, short-term memory, attention, biased competition, probabilistic decision-making, action selection, and decision-making.

This chapter first discusses the concept of the frame and how it helps us to understand the visual patterning of space in late prehistoric Europe. Frames, whether they are wooden picture frames that ...
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This chapter first discusses the concept of the frame and how it helps us to understand the visual patterning of space in late prehistoric Europe. Frames, whether they are wooden picture frames that hold paintings on museum walls or boundary ditches around prehistoric sites, perform the important function of establishing for the viewer the boundaries of that which is to be viewed. The frame tells the viewer what is inside and therefore to be considered and what is outside and therefore can be ignored. The things that prehistoric Europeans placed within frames, their foci of attention, can be understood as diagrams. The chapter then considers some of the visual patterns that persist from the Early Bronze Age through the Late Iron Age, before turning to the character of the changes that took place in ways of seeing in later prehistoric Europe.Less

Frame, Focus, Visualization

Peter S. Wells

Published in print: 2012-08-26

This chapter first discusses the concept of the frame and how it helps us to understand the visual patterning of space in late prehistoric Europe. Frames, whether they are wooden picture frames that hold paintings on museum walls or boundary ditches around prehistoric sites, perform the important function of establishing for the viewer the boundaries of that which is to be viewed. The frame tells the viewer what is inside and therefore to be considered and what is outside and therefore can be ignored. The things that prehistoric Europeans placed within frames, their foci of attention, can be understood as diagrams. The chapter then considers some of the visual patterns that persist from the Early Bronze Age through the Late Iron Age, before turning to the character of the changes that took place in ways of seeing in later prehistoric Europe.

The idea of a disjunctive theory of visual experiences first found expression in J. M. Hinton's pioneering 1973 book Experiences. The first monograph in this exciting area since then, this book ...
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The idea of a disjunctive theory of visual experiences first found expression in J. M. Hinton's pioneering 1973 book Experiences. The first monograph in this exciting area since then, this book develops a comprehensive disjunctive theory, incorporating detailed accounts of the three core kinds of visual experience—perception, hallucination, and illusion—and an explanation of how perception and hallucination could be indiscriminable from one another without having anything in common. In the veridical case, it contends that the perception of a particular state of affairs involves the subject's being acquainted with that state of affairs, and that it is the subject's standing in this acquaintance relation that makes the experience possess a phenomenal character. It argues that when we hallucinate, we are having an experience that, while lacking phenomenal character, is mistakenly supposed by the subject to possess it and shows how this approach is compatible with empirical research into the workings of the brain. It concludes by offering a novel treatment of the many different types of illusion that we can be subject to, which accounts for many illusions, not as special cases of either veridical perception or hallucination but rather as mixed cases that involve elements of both.Less

Perception, Hallucination, and Illusion

William Fish

Published in print: 2009-10-01

The idea of a disjunctive theory of visual experiences first found expression in J. M. Hinton's pioneering 1973 book Experiences. The first monograph in this exciting area since then, this book develops a comprehensive disjunctive theory, incorporating detailed accounts of the three core kinds of visual experience—perception, hallucination, and illusion—and an explanation of how perception and hallucination could be indiscriminable from one another without having anything in common. In the veridical case, it contends that the perception of a particular state of affairs involves the subject's being acquainted with that state of affairs, and that it is the subject's standing in this acquaintance relation that makes the experience possess a phenomenal character. It argues that when we hallucinate, we are having an experience that, while lacking phenomenal character, is mistakenly supposed by the subject to possess it and shows how this approach is compatible with empirical research into the workings of the brain. It concludes by offering a novel treatment of the many different types of illusion that we can be subject to, which accounts for many illusions, not as special cases of either veridical perception or hallucination but rather as mixed cases that involve elements of both.

Current understanding of the basic optical and physiological processes involved in how we see is explained in a number of recent books on the subject by specialists in cognitive psychology and in the ...
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Current understanding of the basic optical and physiological processes involved in how we see is explained in a number of recent books on the subject by specialists in cognitive psychology and in the various branches of neuroscience. This chapter reviews some aspects of the topic that are particularly relevant to the subject of this book. Although in common parlance we speak of seeing with our eyes, in fact we do not see with our eyes, but with our brains. The eyes conduct light, via the retina at the back of the eyeball and the optic nerve, to the various different regions of the brain that are involved in seeing; as many as thirty have been suggested by neuroscientists. Seeing is thus a complex process that takes place in conjunction with other processes in which the brain is involved.Less

Seeing and Shaping Objects

Peter S. Wells

Published in print: 2012-08-26

Current understanding of the basic optical and physiological processes involved in how we see is explained in a number of recent books on the subject by specialists in cognitive psychology and in the various branches of neuroscience. This chapter reviews some aspects of the topic that are particularly relevant to the subject of this book. Although in common parlance we speak of seeing with our eyes, in fact we do not see with our eyes, but with our brains. The eyes conduct light, via the retina at the back of the eyeball and the optic nerve, to the various different regions of the brain that are involved in seeing; as many as thirty have been suggested by neuroscientists. Seeing is thus a complex process that takes place in conjunction with other processes in which the brain is involved.

The preceding chapters examined three categories of objects—pottery, fibulae, and swords with their scabbards—and two ways of manipulating objects—arrangements in graves and performances involving ...
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The preceding chapters examined three categories of objects—pottery, fibulae, and swords with their scabbards—and two ways of manipulating objects—arrangements in graves and performances involving human bodily action with objects—over the two-thousand-year period from the Early Bronze Age to the end of the prehistoric Iron Age. The focus has been on visual aspects of objects and the changes in their visual character over time. This chapter synthesizes the material laid out in chapters 5 through 10. It draws attention to the consistency of the patterns in the visual character of material culture in each of the three main periods of time considered in this book, and to the character of the changes that took place in the fifth century BC and in the second century BC.Less

Changing Patterns in Objects and in Perception

Peter S. Wells

Published in print: 2012-08-26

The preceding chapters examined three categories of objects—pottery, fibulae, and swords with their scabbards—and two ways of manipulating objects—arrangements in graves and performances involving human bodily action with objects—over the two-thousand-year period from the Early Bronze Age to the end of the prehistoric Iron Age. The focus has been on visual aspects of objects and the changes in their visual character over time. This chapter synthesizes the material laid out in chapters 5 through 10. It draws attention to the consistency of the patterns in the visual character of material culture in each of the three main periods of time considered in this book, and to the character of the changes that took place in the fifth century BC and in the second century BC.

Vision and memory are two of the most intensively studied topics in psychology and neuroscience, and the intersection between them — visual memory — is emerging as a fertile ground for research. ...
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Vision and memory are two of the most intensively studied topics in psychology and neuroscience, and the intersection between them — visual memory — is emerging as a fertile ground for research. Certain memory systems appear to specialize in maintaining visually encoded information. Vision provides the primary input to more general memory systems. These more general systems link and integrate visual memory with other perceptual and cognitive processes. As a result, visual perception cannot be understood independently of visual memories, which support the mapping of perceptual input onto existing knowledge structures that guide and constrain perceptual selection. This book provides an account of visual memory systems. The chapters provide both a broad overview of each topic and a summary of the latest research. They also present new perspectives that advance our theoretical understanding of visual memory and suggest directions for future research. After an introductory overview by the editors, chapters address visual sensory memory (iconic memory), visual short-term memory, and the relationship between visual memory and eye movements. Visual long-term memory is then reviewed from several different perspectives, including memory for natural scenes, the relationship between visual memory and object recognition, and associative learning. The final chapters discuss the neural mechanisms of visual memory and neuropsychological deficits in visual memory.Less

Visual Memory

Published in print: 2008-08-12

Vision and memory are two of the most intensively studied topics in psychology and neuroscience, and the intersection between them — visual memory — is emerging as a fertile ground for research. Certain memory systems appear to specialize in maintaining visually encoded information. Vision provides the primary input to more general memory systems. These more general systems link and integrate visual memory with other perceptual and cognitive processes. As a result, visual perception cannot be understood independently of visual memories, which support the mapping of perceptual input onto existing knowledge structures that guide and constrain perceptual selection. This book provides an account of visual memory systems. The chapters provide both a broad overview of each topic and a summary of the latest research. They also present new perspectives that advance our theoretical understanding of visual memory and suggest directions for future research. After an introductory overview by the editors, chapters address visual sensory memory (iconic memory), visual short-term memory, and the relationship between visual memory and eye movements. Visual long-term memory is then reviewed from several different perspectives, including memory for natural scenes, the relationship between visual memory and object recognition, and associative learning. The final chapters discuss the neural mechanisms of visual memory and neuropsychological deficits in visual memory.

Visual ecology is the study of how animals use visual systems to meet their ecological needs, how these systems have evolved, and how they are specialized for particular visual tasks. This book ...
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Visual ecology is the study of how animals use visual systems to meet their ecological needs, how these systems have evolved, and how they are specialized for particular visual tasks. This book provides the first up-to-date synthesis of the field to appear in more than three decades. Featuring some 225 illustrations, including more than 140 in color, spread throughout the text, the book begins by discussing the basic properties of light and the optical environment. It then looks at how photoreceptors intercept light and convert it to usable biological signals, how the pigments and cells of vision vary among animals, and how the properties of these components affect a given receptor's sensitivity to light. The book goes on to examine how eyes and photoreceptors become specialized for an array of visual tasks, such as navigation, evading prey, mate choice, and communication. A timely and much-needed resource for students and researchers alike, the book also includes a glossary and a wealth of examples drawn from the full diversity of visual systems.Less

Visual Ecology

Thomas W. CroninSönke JohnsenN. Justin MarshallEric J. Warrant

Published in print: 2014-08-10

Visual ecology is the study of how animals use visual systems to meet their ecological needs, how these systems have evolved, and how they are specialized for particular visual tasks. This book provides the first up-to-date synthesis of the field to appear in more than three decades. Featuring some 225 illustrations, including more than 140 in color, spread throughout the text, the book begins by discussing the basic properties of light and the optical environment. It then looks at how photoreceptors intercept light and convert it to usable biological signals, how the pigments and cells of vision vary among animals, and how the properties of these components affect a given receptor's sensitivity to light. The book goes on to examine how eyes and photoreceptors become specialized for an array of visual tasks, such as navigation, evading prey, mate choice, and communication. A timely and much-needed resource for students and researchers alike, the book also includes a glossary and a wealth of examples drawn from the full diversity of visual systems.

Visual information can be processed at pre-conscious as well as conscious levels. Understanding the factors that determine whether or not a stimulus reaches phenomenal awareness and the fate of ...
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Visual information can be processed at pre-conscious as well as conscious levels. Understanding the factors that determine whether or not a stimulus reaches phenomenal awareness and the fate of stimulus information that remains at preconscious levels, poses major challenges to current research in visual cognition and neuroscience. First published in 1984, Visual Masking was a classic text in the field of cognitive psychology. In the years since, considerable advances that have been made in the cognitive neurosciences have been accompanied by a growing interest in the topic of consciousness. The current, 2nd edition takes into account these new findings and research interests. Incorporating much new, and deleting some old materials, this book focuses on visual masking as a technique of making ‘time slices’ on a millisecond scale through conscious and pre-conscious vision. The result is a detailed description of the temporal dynamics that comprise the microgenesis of visual object perception from the time a stimulus is presented on the retinae to the time, several hundreds of milliseconds later, of its registration at pre-conscious, behavioural, and at conscious, perceptual levels. The book takes a highly integrative approach, relating visual masking within a wide compass, not only to the study of conscious perception, but also to related spatio-temporal phenomena of vision such as motion perception, attention, and to a variety of visual deficits.Less

Visual Masking : Time slices through conscious and unconscious vision

Bruno BreitmeyerHaluk Ogmen

Published in print: 2006-04-20

Visual information can be processed at pre-conscious as well as conscious levels. Understanding the factors that determine whether or not a stimulus reaches phenomenal awareness and the fate of stimulus information that remains at preconscious levels, poses major challenges to current research in visual cognition and neuroscience. First published in 1984, Visual Masking was a classic text in the field of cognitive psychology. In the years since, considerable advances that have been made in the cognitive neurosciences have been accompanied by a growing interest in the topic of consciousness. The current, 2nd edition takes into account these new findings and research interests. Incorporating much new, and deleting some old materials, this book focuses on visual masking as a technique of making ‘time slices’ on a millisecond scale through conscious and pre-conscious vision. The result is a detailed description of the temporal dynamics that comprise the microgenesis of visual object perception from the time a stimulus is presented on the retinae to the time, several hundreds of milliseconds later, of its registration at pre-conscious, behavioural, and at conscious, perceptual levels. The book takes a highly integrative approach, relating visual masking within a wide compass, not only to the study of conscious perception, but also to related spatio-temporal phenomena of vision such as motion perception, attention, and to a variety of visual deficits.

The human visual system consists of a system for inspecting objects, starting with the fovea in the retina, and a system for noticing which objects should be inspected, and directing the eyes to look ...
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The human visual system consists of a system for inspecting objects, starting with the fovea in the retina, and a system for noticing which objects should be inspected, and directing the eyes to look at them. In daylight, the cones are the photoreceptors used, with three types, leading to trichromatic color vision. At night, the rods are active. As the eyes move, the world appears to be stationary, which is accomplished by noticing and carrying forward a limited number of objects from one snapshot to the next. Most aspects of vision are relative—the brightness, color, motion, and depth of an object are all seen relative to the background. Finally, absence of activity in the neurons of the visual system is interpreted as continuity with the rest of the scene, so that lesions in the brain may simply not be noticed.Less

Introduction

Nigel Daw

Published in print: 2012-01-19

The human visual system consists of a system for inspecting objects, starting with the fovea in the retina, and a system for noticing which objects should be inspected, and directing the eyes to look at them. In daylight, the cones are the photoreceptors used, with three types, leading to trichromatic color vision. At night, the rods are active. As the eyes move, the world appears to be stationary, which is accomplished by noticing and carrying forward a limited number of objects from one snapshot to the next. Most aspects of vision are relative—the brightness, color, motion, and depth of an object are all seen relative to the background. Finally, absence of activity in the neurons of the visual system is interpreted as continuity with the rest of the scene, so that lesions in the brain may simply not be noticed.

This book examines the phenomenon of ‘yoof’ television programmes such as Network 7, The Word, The Big Breakfast, Snub TV, and Gamesmaster. Between 1987 and 1995 these and other related programmes ...
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This book examines the phenomenon of ‘yoof’ television programmes such as Network 7, The Word, The Big Breakfast, Snub TV, and Gamesmaster. Between 1987 and 1995 these and other related programmes formed part of a high-profile genre that in terms of both the personnel involved and their visual style continue to be influential in British television today. Examining these programmes the author reflects on the way in which the contemporary youth audience – Generation X – were being addressed. The author identifies an ambivalent viewing sensibility – ‘cynicism and enchantment’ – which encapsulates the attitude expressed by both the programmes and the audience. The distinctive aspect of the book is the way in which the author concentrates on the spatial and visual aspects of television. In particular her concern is to re-evaluate television as a specific experience, and one which has a central importance in young people's formation of identity and their sense of being in the world. Her central thesis also suggests that while television must necessarily be related to other visual media, it should be understood as having distinct aesthetic and phenomenological qualities of its own.Less

British Youth Television : Cynicism and Enchantment

Karen Lury

Published in print: 2001-06-28

This book examines the phenomenon of ‘yoof’ television programmes such as Network 7, The Word, The Big Breakfast, Snub TV, and Gamesmaster. Between 1987 and 1995 these and other related programmes formed part of a high-profile genre that in terms of both the personnel involved and their visual style continue to be influential in British television today. Examining these programmes the author reflects on the way in which the contemporary youth audience – Generation X – were being addressed. The author identifies an ambivalent viewing sensibility – ‘cynicism and enchantment’ – which encapsulates the attitude expressed by both the programmes and the audience. The distinctive aspect of the book is the way in which the author concentrates on the spatial and visual aspects of television. In particular her concern is to re-evaluate television as a specific experience, and one which has a central importance in young people's formation of identity and their sense of being in the world. Her central thesis also suggests that while television must necessarily be related to other visual media, it should be understood as having distinct aesthetic and phenomenological qualities of its own.

This book offers a general account of the forms of mental representation that we call ‘sensory’. To sense something, one must have some capacity to discriminate among sensory qualities; but there are ...
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This book offers a general account of the forms of mental representation that we call ‘sensory’. To sense something, one must have some capacity to discriminate among sensory qualities; but there are other requirements. What are they, and how can they be put together to yield full-blown sensing? Drawing on the findings of current neuroscience, the author proposes and defends the hypothesis that the various modalities of sensation share a generic form that he calls ‘feature-placing’. Sensing proceeds by picking out place-times in or around the body of the sentient organism, and characterizing qualities (features) that appear at those place-times. Such feature-placing is a primitive kind — probably the most primitive kind — of mental representation. Once its peculiarities have been described, many of the puzzles about the intentionality of sensation, and the phenomena that lead some to label it ‘pseudo-intentional’, can be resolved. The hypothesis casts light on many other troublesome phenomena, including the varieties of illusion, the problem of projection, the notion of a visual field, the location of after-images, the existence of sense-data, and the role of perceptual demonstratives.Less

A Theory of Sentience

Austen Clark

Published in print: 2000-03-09

This book offers a general account of the forms of mental representation that we call ‘sensory’. To sense something, one must have some capacity to discriminate among sensory qualities; but there are other requirements. What are they, and how can they be put together to yield full-blown sensing? Drawing on the findings of current neuroscience, the author proposes and defends the hypothesis that the various modalities of sensation share a generic form that he calls ‘feature-placing’. Sensing proceeds by picking out place-times in or around the body of the sentient organism, and characterizing qualities (features) that appear at those place-times. Such feature-placing is a primitive kind — probably the most primitive kind — of mental representation. Once its peculiarities have been described, many of the puzzles about the intentionality of sensation, and the phenomena that lead some to label it ‘pseudo-intentional’, can be resolved. The hypothesis casts light on many other troublesome phenomena, including the varieties of illusion, the problem of projection, the notion of a visual field, the location of after-images, the existence of sense-data, and the role of perceptual demonstratives.

This chapter explores the potential use of visual sources, together with the methods employed for studying them, such as iconography or iconology, for the history of ‘ancient Israel’. It describes ...
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This chapter explores the potential use of visual sources, together with the methods employed for studying them, such as iconography or iconology, for the history of ‘ancient Israel’. It describes the theoretical and conceptual framework, particularly the notion of ‘eyewitnessing’, and considers the method, particularly iconography. The chapter also presents case examples chosen from monuments which are so well known to historians of ancient Israel that they are well suited to illustrate both the pitfalls of more conventional interpretations and the potential of alternative approaches. Before turning to the sources – namely visual evidence that may be related to the history of ancient Israel and Judah – the chapter discusses the state of the art among fellow historians in neighbouring disciplines, including those belonging to the so-called ‘humanities’ (or arts and letters). It also considers visual art and history, the metaphor of legal investigation, the balancing of testimony, and the particular status of an eyewitness.Less

Neither Eyewitnesses, Nor Windows to the Past, but Valuable Testimony in its Own Right: Remarks on Iconography, Source Criticism and Ancient Data-processing

CHRISTOPH UEHLINGER

Published in print: 2007-10-25

This chapter explores the potential use of visual sources, together with the methods employed for studying them, such as iconography or iconology, for the history of ‘ancient Israel’. It describes the theoretical and conceptual framework, particularly the notion of ‘eyewitnessing’, and considers the method, particularly iconography. The chapter also presents case examples chosen from monuments which are so well known to historians of ancient Israel that they are well suited to illustrate both the pitfalls of more conventional interpretations and the potential of alternative approaches. Before turning to the sources – namely visual evidence that may be related to the history of ancient Israel and Judah – the chapter discusses the state of the art among fellow historians in neighbouring disciplines, including those belonging to the so-called ‘humanities’ (or arts and letters). It also considers visual art and history, the metaphor of legal investigation, the balancing of testimony, and the particular status of an eyewitness.

This introductory chapter talks about how every creature is guided by its eyes as it carries out its accustomed behaviors. Each animal's eyes allows it to execute the behavior necessary for its ...
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This introductory chapter talks about how every creature is guided by its eyes as it carries out its accustomed behaviors. Each animal's eyes allows it to execute the behavior necessary for its survival. This study of how visual systems function to meet the ecological needs of animals is called visual ecology. Researchers who work at various levels of inquiry, from genes to behavior, call themselves visual ecologists, but all are primarily concerned with how animals use vision for natural tasks and behaviors. Although the outcomes of visual ecological research may well have implications for health or may be applicable for use in engineering or technology, the research itself centers on the animal of interest and on how it employs its visual system to meet its own ecological needs.Less

Introduction

Thomas W. CroninSönke JohnsenN. Justin MarshallEric J. Warrant

Published in print: 2014-08-10

This introductory chapter talks about how every creature is guided by its eyes as it carries out its accustomed behaviors. Each animal's eyes allows it to execute the behavior necessary for its survival. This study of how visual systems function to meet the ecological needs of animals is called visual ecology. Researchers who work at various levels of inquiry, from genes to behavior, call themselves visual ecologists, but all are primarily concerned with how animals use vision for natural tasks and behaviors. Although the outcomes of visual ecological research may well have implications for health or may be applicable for use in engineering or technology, the research itself centers on the animal of interest and on how it employs its visual system to meet its own ecological needs.